The construction of the new Denver International Airport offers the opportunity to describe the epidemiology of work-related injury and illness in several sectors of a hazardous industry, including road building, subway tunnelling, and construction of commercial buildings, such as terminals and concourses. The specific aims are to describe the magnitude and rates of work-related morbidity by trade and project; to assess modifiable risk factors for construction-related health problems; and to evaluate the impacts on morbidity and costs of an owner-controlled insurance program and workers' compensation reform in Colorado. Hypotheses pertinent to prevention of construction-related health' problems will be answered with four intertwined study designs: 1) a cohort study of all airport construction workers examining workers' compensation claims as the health outcome; 2) an evaluation of claims rates in relation to contractor characteristics obtained through a cross-sectional interview survey of contractors; 3) a comparison of claims experience from the airport construction with that of Colorado's and the nation's construction industry; and 4) an evaluation of the preventive and economic effects of the legislative reform in Colorado's workers' compensation law that occurred during airport construction. Workforce and compensation claims data bases for all airport construction contractors are available for these analyses through Denver County's owner-controlled insurance plan for the new airport. Comparative data are available from the National Council on Compensation Insurance, the Colorado Division of Workers' Compensation in the Colorado Department of Labor, and the Bureau of Labor Statistics, U.S. Department of Labor. Risk factors for work-related injury and illness identified in this $2.924 billion construction project, which hired 46,354 workers on 2,928 contracts, will be useful in planning preventive interventions in the construction industry.